Destroy objects at end of scope

[dkolsen-pgi]

ClangIR does not call destructors when objects go out of scope. It does that silently, not even a "NYI" message.

$ cat basic.cpp
extern "C" int printf(char const*, ...);
struct A {
  A() { printf("++A\n"); }
  ~A() { printf("--A\n"); }
};
int main() {
  {
    A a;
  }
  printf("Done\n");
}
$ clang++ basic.cpp ; ./a.out
++A
--A
Done
$ clang++ -fclangir-enable basic.cpp ; ./a.out
++A
Done

[bcardosolopes]

We actually do clang/test/CIR/CodeGen/dtors.cpp but we're still missing some more basic cases. This should be an assertion, but it's probably due to my workaround in 0a59c5c to unbreak an internal build. Do you intend to work on this? If not I can take a look sooner than later.

[dkolsen-pgi]

I am not planning to work on this right away. I am working on vector types #284 right now. (Can I somehow get permission to make some changes to issues, at least to assign them to myself?)

[bcardosolopes]

Can I somehow get permission to make some changes to issues, at least to assign them to myself?

Done, let me know if it works!

[bcardosolopes]

First part of the fix: d732147, next is to fix some dtor codegen issues.

Note that this would still crash if -fexceptions is on, but I'm tackling that separately as part of adding support for exceptions.

[bcardosolopes]

Fixed now after both 7683175 and 2aac175, the example runs on my macOS laptop, let me know if it doesn't work on Linux for any reason.

[dkolsen-pgi]

The original test program now works for me. Destructors are called when falling off the end of a scope. But destructors are not called when jumping out of a scope. This program is missing some destructor calls. Should I open a new issue for this, or reopen this one?

extern "C" int printf(char const*, ...);
struct A {
  A() { printf("++A\n"); }
  A(int n) { printf("++A(%d)\n", n); }
  ~A() { printf("--A\n"); }
};
void test(int x) {
  printf("test(%d)\n", x);
  A a;
  if (x == 1) return;
  {
    A b(3);
    if (x == 2) return;
  }
  if (x == 3) return;
}
int main() {
  test(1);
  test(2);
  test(3);
  test(4);
}

[bcardosolopes]

Thanks for reporting more variations, created #348 to track it!